The present invention relates to a security seal placed around collars which are used to tension counterbalance springs in garage door assemblies.
Large, vertical opening doors, such as commercial and residential sectional garage doors, usually require mechanisms to counterbalance the weight of the door in order to minimize door opening efforts and to control movement of the door from an open to a closed position. Large sectional garage doors for commercial and residential applications may be manually or power operated. In either case, but particularly for manual operation, counterbalance mechanisms have been used for many years to counterbalance the weight of the door and control its opening and closing movements so that one person can easily control operation of the door. Counterbalance mechanisms are also advantageous for power operated vertical opening doors since they reduce motor power requirements and the strength of the door opening and closing mechanism. In other words, lighter weight, lower cost door control mechanisms may be used if a counterbalance mechanism is connected to the door to assist the opening and closing action. Still further, the provision of a counterbalance mechanism minimizes the chance of rapid and uncontrolled closing of the door in the event of failure of the door opening and closing mechanism, which can result in injury or damage.
A widely used type of counterbalance apparatus comprises, generally, a pair of spaced apart cable drums connected to flexible cables, which in turn are connected to lower opposed edges of the garage door. The cable drums are usually mounted on a shaft which is supported above the door opening and is connected to one or more torsion springs which are fixed at one end to the shaft and are secured to the wall at the opposite end so that the cable drums are biased to rotate in a direction which winds the cables onto the drum and counteracts the weight of the door connected to the cables. The torsion springs are adjusted to properly balance the weight of the door so that minimal opening and closing effort is required, either manually or motor controlled.
Conventional, low cost adjustment mechanism for the above mentioned type of counterbalance apparatus, and widely used in the door industry, is characterized by generally cylindrical collars commonly also referred to as xe2x80x9cplugsxe2x80x9d (or cones) which are connected to the so-called fixed ends of the torsion springs and are mounted on the aforementioned shaft for adjusting the deflection of the springs to preset the counterbalance effort. The aforementioned collars usually include one or more setscrews which lock the collars to the shaft to prevent rotation except during adjustment of the spring deflection. The collars also include sockets for receiving winding bars whereby the springs are manually preset by rotating the collars using the winding bars and then locking-the collars to the shaft with the set screws.
One problem associated with this type of counterbalance apparatus, or any other type of counterbalancing mechanism which uses winding collars and tensioning springs, is that to a casual observer, they appear harmless. Consequently, some people will attempt to unscrew the setscrews, for any number of reasons. However, the combination of the collars and the tensioning springs maintains a considerable torque on the shaft. Once the setscrews are loosened, the torque causes the collars to rotate about the shaft with high velocity and high force, which often results in serious personal injury including death or serious property damage.
It is an object of the invention to provide a security seal for such collars used for tensioning springs in garage door assemblies. Such a seal will help prevent people from being injured by any component under tension (or torque) by warning and blocking access to the collar. In accordance with the invention, this object is achieved with a seal comprising a generally longitudinal piece of flexible material having two opposite ends, the opposite end being provided with cooperating lock means for locking the opposite ends together, and means for preventing access to at least one socket and at least one screw used to maintain tension on the plug when the seal is placed about the collar.
In a preferred embodiment of the invention, this object is achieved with a security seal for a collar comprising:
a generally longitudinal piece of flexible material having two opposite ends, the opposite ends being provided with cooperating lock means for locking the opposite ends together;
at least one cup adapted to receive the at least one set screw therein; and
at least two protuberances, each of said protuberances being adapted to fit within a corresponding winding hole; whereby the at least one cup and the at least two protuberances are disposed on said security seal so that when said seal is locked about said collar, said cup and said protuberances are in registration with the at least one set screw and the at least two winding holes respectively.
Once the seal is wrapped around the collar and locked, a casual observer will not be tempted to break the seal and attempt to unscrew the setscrews. Preferably, the seal is made of a color representing danger, and may further be inscribed with appropriate warnings.